1. Technical Field
The disclosure generally relates to light emitting diode (LED) lamps, and particularly to an LED lamp which is capable of providing both normal and emergency illuminations.
2. Description of Related Art
To resolve the problem of global warming and natural resource exhaustion, low power consuming electrical devices are required. LED lamps are developed to meet the power-saving trend. LED lamps having LEDs (light emitting diodes) are preferable for use to CCFLs (cold cathode fluorescent lamps) and other traditional lamps due to the excellent properties, including high brightness, low power consumption, long lifespan, environment friendliness, rapid start-up, directivity, etc of the LEDs.
Nowadays, LEDs have been used in both a general lamp for normal illumination and an emergency lamp for emergency illumination. However, the conventional LED-type general lamp is individually designed for normal illumination where an external alternating current (AC) power source is readily available, without making the most use of an environment illumination enhanced the insufficient normal illumination by auxiliary illumination for energy-saving. The conventional LED-type emergency illumination is typically installed in places such as hallways, stairs, passageways, and other areas needing an emergency illumination, without making the most use of the environment illumination extended the emergency illumination period by auxiliary illumination for safety. The conventional LED-type emergency illumination is constantly inactive, except when the AC power source to the conventional LED-type general lamp is interrupted. To equip a same area with both the general and emergency lamps is costly in money and space.
Therefore, it is desirable to provide an LED lamp which is capable of providing normal, auxiliary and emergency illuminations.